Pump Start/Stop

[mengbly]

Hello everbody

can anyone please help me in answering the below questions

1. what is the logic behind number of start/stops for domestic water pumps, is there any formula or calculations for the same ?

2. How to calculate the expansion tank size for the booster pumps, is the tanks size also related to the number of starts and stops of the pump??

thanks

 

[Artisi]

It is dependant on the electric motor and the heat rise from continual starts which doesn't allow it to cool sufficiently. It has nothing to do with the pump. The information is from the motor manufacturer based on testing.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[77JQX]

As Artisi suggests, once you have the allowable number of starts per hour from the motor manufacturer, then you can size the holding tank for the expected demand and allowable starts per hour. This is the same problem faced in the design of sewage lift stations, specifically the wet well size. If you google "wet well sizing" you can find lots of guidance. You'll need to substitute 'water demand' for 'sewage inflow', but otherwise, it's the same problem.

 

[bimr]

Franklin electric will provide this information for you.

http://www.franklin-electric.com/aim-manual/page-3.aspx